A number of medicaments that are presently administered orally must be prescribed to patients in dosages which are tailored to the mass, age and medical history of the patient. Medications in pill or capsule form are limited by the discrete dosages of the particular tablet or capsule size. Pills may sometimes be scored along their diameter to provide roughly half the dosage when broken along the score line. However, this rough method is inaccurate and inadequate other than for half-dosages. By way of example, sodium warfarin requires personalized dosing to achieve the desired therapeutic effect and to avoid undesirable side effects such as bleeding. Available multi-potency tablets usually require unconventional, confusing dosing patterns to achieve the appropriate therapeutic response.
Some medicaments lend themselves to a liquid form which is somewhat more adaptable in dosage. However, liquids are less convenient and require the patient to be responsible for measurement of the dosages. Although liquid medicaments are theoretically infinitely meterable, in practice, the dosages commonly used are rough and inaccurate. Liquids are somewhat less portable and often require refrigeration.
Accuracy in the treatment of a patient undergoing a drug therapy regimen also requires the patient to take the appropriate dosage over an extended period of time at appropriate intervals. Some treatments require a uniform dosage over uniform intervals of time, while other medicaments require "tapered dosages" which may increase, level off and decrease over the treatment period. An easily varied dosage regimen which encourages patient compliance with the regimen is greatly needed. None of these treatment regimens are easily accomplished using tablets, capsules or liquid medicaments.